Index: wp-includes/css/buttons.css
===================================================================
--- wp-includes/css/buttons.css	(revision 27076)
+++ wp-includes/css/buttons.css	(working copy)
@@ -174,6 +174,7 @@
 	box-shadow: none !important;
 	text-shadow: 0 1px 0 #fff !important;
 	cursor: default;
+	pointer-events: none;
 }
 
 /* ----------------------------------------------------------------------------
@@ -230,6 +231,7 @@
 	box-shadow: none !important;
 	text-shadow: 0 -1px 0 rgba(0,0,0,0.1) !important;
 	cursor: default;
+	pointer-events: none;
 }
 
 /* ----------------------------------------------------------------------------